If you don't know what to do, read the Answers.com article on how to play. The game involves four different particles falling from the top of the screen, which all look and move similar to sand. The particles resemble sand, water, salt, and oil in color. Along with these four, additional elements can be placed on the screen with the mouse, some that are solid and stationary instead of flowing. By mixing the different elements together, many colorful designs, complex structures, and systems can be created.
Screenshots: Pic-1, Pic-2, Pic-3, Pic-4, Pic-5, Pic-6, Pic-7. Tim DeBruine of Craic Wisely wrote/sang a melodious song: "Falling Sand Song" (MP3).

[Game found on DOFI-Blog via Fark]
[I, Chirag Mehta, take no credit for creating this game or copyrights thereof. This game is simply for my personal use.]